Vehicle turn signals, while having been in use on commercially available motor vehicles for about 70 years, have changed little since their first application. A vehicle steering wheel is commonly comprised of a column, central hub and annular ring with various components including a turn signal activation switch or switches. Typically turn signal lights are operated by a “stalk switch” or lever located to one side of the steering wheel. The stalk switch is moved upward to signal a right-hand turn and downward to signal a left-hand turn. When the stalk switch is moved up, lights located generally in the front and rear right side fenders begin to blink. Similarly, when the stalk switch is moved down, lights located generally in the front and rear left side fenders begin to blink. More typically, the stalk switch includes four positions, two up and two down. The first positions, either up or down, operate the turn signals but the stalk switch returns to the off position, or center, when released. The second of the positions maintains the turn signals on even when the stalk switch is released and shuts off after the steering wheel has been turned a fixed rotation and then returned to an approximately “wheels straight” position.
With the mechanism described above, several well-known problems arise. For example, turn signals may be left on with the signal lights “blinking” well after a turn is completed. A common condition is that signal lights turn off prematurely if the steering wheel is momentarily turned even slightly away from the direction of the turn. Another common condition is the failure of a turn signal to engage if the steering wheel is slightly turned in one direction and the driver attempts to signal a turn in the opposite direction. Such problems have existed since the turn signal was first installed on a motor vehicle.
Recent advances have addressed different physical configurations and different control mechanisms for improving on the operation of the turn signal. For example, more sophisticated in-vehicle computer hardware, such as those systems offered by RLP Engineering, Dayton, Ohio, has allowed for the real-time management of turn signal operation to address problems such as those described above. In such a system, vehicle speed, steering wheel position and other data are monitored in real time to determine whether the vehicle is turning and when the turn has been completed. However, even in such a computer-based system, the turn signal is activated by moving a stalk switch up or down to turn on the switch and the corresponding turn signal light. The turn signal of this computer-based system can be manually switched off by a button on the stalk switch. One disadvantage of this system is that one hand must be removed from the steering wheel in order to operate the stalk switch.
Other modifications of the turn signal have focused on replacing the stalk switch with buttons or paddles located in the hub of the steering wheel, such as the apparatuses illustrated in U.S. Pat. No. 5,739,491 to Crosson, Jr. and U.S. Patent Application Publication 2009/01655592 to Sakai et al. However, such modifications do not address the disadvantages described above. Specifically, placing the turn signal activation switches in the hub of the steering wheel still requires the driver either to remove one hand from the steering wheel or to release his grasp on the wheel in order to operate the hub-mounted switch. Such modifications also do not address problems arising when the turn signal is left on after a turn or when the turn signal prematurely turns off.
Spoke-mounted turn signal activation switches, such as those envisioned in U.S. Pat. No. 5,823,666 to Kingsolver, do not eliminate the requirement that a driver's hand must be repositioned to activate the switch even if the hand remains in contact with the steering wheel. The natural position of the driver's thumb is aligned with the rim of the steering wheel or wrapped partially around the rim of the steering wheel when the wheel is gripped. Therefore, a driver must release his/her grip from the steering wheel in order to re-position the thumb on the spoke mounted switch. This change in position is necessary regardless of the location of the spoke around the internal diameter of the steering wheel. If the driver's hand is located proximal to or in contact with the spoke and above the spoke, the driver must rotate the hand downward to contact the spoke-mounted switch. If the driver's hand is located proximal to or in contact with the spoke and below the spoke, the driver must either rotate the hand downward to contact the spoke-mounted switch or move the hand upward and rotate the thumb downward to make contact with the switch. Such a rotation or movement requires that the driver release his/her grip from the wheel in order to move the hand.
Even though the expressed advantage of placing the turn signal switch in the spoke of the steering wheel was that it would permit turn signal operation without the driver needing to remove his/her hands from the steering wheel, in practice a driver must re-position his/her hands to press the spoke-mounted switches. As addressed above, such a design, like those placing the turn signal activation switch in the steering wheel hub, permits the operation of the switch without removing one hand from the steering wheel in very limited and still undesirable positions of the hand relative to the steering wheel.
In U.S. Pat. No. 6,961,644 to Mercier et al., a steering wheel with hot buttons placed at the “10 o'clock” and “2 o'clock” positions on the steering wheel rim was posited. According to this publication, such a system would allow a driver to activate the hot buttons, thus activating a turn signal, by using a thumb. Such a process of activating a turn signal, according to this publication, would not require a driver “to even move his or her hands much.” However, tests conducted demonstrated that the hot buttons of this hypothetical device cannot be pressed if the driver maintains a fully-wrapped four finger grip anywhere on the top half of the steering wheel. Therefore, this hypothetical device suffers from all of the problems of other earlier devices because it merely relocates the functionality of the turn signal stalk switch to hot buttons on the rim of the steering wheel. Turn signals may be inadvertently turned on by misplacement of the hand or remain on with the signal lights “blinking” well after a turn is completed. Turn signal lights may turn off prematurely if the steering wheel is momentarily turned even slightly away from the direction of the turn. Furthermore, with this hypothetical device the driver must loosen his or her grip on the steering wheel so that the hand may be rotated in order to put the thumb in position to operate the hot buttons.
According to “Hands-On: A Practical Measure of the Perceived Risk of the Driving Context,” J. A. Thomas and D. Walton, Transit NZIHT 7th Annual Conference (2005), most drivers place both hands somewhere on the top half of the steering wheel when driving under higher-risk or complex conditions. It follows then that most drivers feel that driving with two hands on the top half of the steering wheel, particularly during high-risk or complex driving situations, provides more control over the vehicle.
A driver in many instances must remove one hand from the steering wheel in order to operate a stalk switch-activated turn signal because the stalk switch is typically not located in close enough proximity to the steering wheel. Regardless of the driver's hand position, one hand must always be removed from the steering wheel in order to operate a stalk switch-activated turn signal. Where the turn signal switches are located in the hub of the wheel, the result is essentially the same. Either the driver's hand must be removed from the steering wheel to activate the hub-mounted switch or the hand must be turned so that the thumb of the driver's hand can reach the hub-mounted switch. In turning the hand to stretch the thumb to reach the switch, a driver must release his/her grip on the steering wheel, even if the hand remains in contact with the steering wheel. Similarly, when the turn signal switch is located in a spoke of the steering wheel, the driver must reposition his or her hand in order to operate the spoke-mounted switch.
It would therefore be advantageous to have a turn signal activation switch and system which does not require that a driver release his/her grip from the steering wheel in order to operate the switch. It would be a further advantage to have a turn signal activation switch and system which can be operated during high-risk or complex driving situations while maintaining a two-handed grip on the steering wheel. It would be an additional advantage to have a turn signal activation switch and system that would not prematurely turn off or remain on after a turn. It would be yet a further advantage to have a turn signal activation switch and system that could not be accidently operated.